The effect of interfacial waves on the turbulence structure of stratified air/water pipe flow

Statistical characterization of interfacial waves in turbulent stratified gas-liquid pipe flows

“…The data under investigation was acquired during an experimental campaign conducted at the Hydrodynamic Laboratory at the University of Oslo. The experimental techniques PIV, conductance probing and hot-wire anemometry were combined to study of air-water flow in pipes (Ayati et al, 2014(Ayati et al, , 2015(Ayati et al, , 2016. In this paper, we will only focus on the data stemming from the wave gauge, i.e.…”

“…Nevertheless, the next generation of flow simulators are expected to include "regime-capturing" approaches which rely on finer grid resolution (Issa & Kempf, 2003;Carneiro et al, 2011;Danielson et al, 2012;Nieckele et al, 2011;Nieckele & Carneiro, 2017). Furthermore, recent developments in experimental investigation of this system (Birvalski et al, 2014(Birvalski et al, , 2015(Birvalski et al, , 2016Ayati et al, 2014Ayati et al, , 2015Ayati et al, , 2016Ayati et al, , 2017André & Bardet, 2017), have shown that the overall bulkflow is strongly coupled with wavy interface. To this end, detailed description of measured interfacial waves is expected to be of valuable use with respect to validation of models and CFD simulations.…”

Investigation of breaking and non-breaking solitary waves and measurements of swash zone dynamics on a 5° beach

“…A range of different measurement techniques e.g. conductance probes (Strand, 1993), PIV (Ayati et al (2014), Ayati et al (2015)), hot wire measurements (Ayati et al, 2016) and optical investigation Sanchis et al (2011) have been utilized to establish physical parameters such wave amplitude, wave spectra, and velocities in both liquid and gas phase Ayati et al (2015).…”

Optimization of the Interfacial Shear Stress and Assessment of Closure Relations for Horizontal Viscous Oil-Gas Flows in the Stratified and Slug Regimes

“…One of the greatest challenges in the use of 1D gas-liquid models is the adequate modelling of the interfacial shear stress, for being a parameter in which complex phenomena (interfacial waves, relation between them and the turbulence of the phases, among others) are included (Hanratty, 2013;Ayati et al, 2016;André & Bardet, 2017). For viscous oil-gas flows, an added difficulty is related to the high oil viscosity, which induces several effects on the interfacial dynamics that directly impacts the interfacial shear stress (Andritsos & Hanratty, 1987b;Newton et al, 1999;Matsubara & Naito, 2011).…”

“…Although, it is known (Andritsos & Hanratty, 1987a;Andreussi & Persen, 1987) that the presence of interfacial waves should increase the interfacial shear stress when compared to a smooth interface, the exact physical mechanisms embedded in this relation are not yet fully understood. That is because of the complex relation between the turbulent structures of the phases with the interfacial dynamics (Ayati et al, 2016) and the way it affects the cross sectional velocity profile in each phase (Belcher & Hunt, 1993). In addition, how the different components (tangential and normal to the interface) of the interfacial shear stress should be accounted for and the questions regarding the consideration of its viscous and pressure contributions increase even more the challenge of modelling the referred parameter (André & Bardet, 2017).…”